The present invention relates to hand grenades and particularly to a new and improved grenade fuze with spin-operated firing means. A hand grenade is usually provided with a fuze including a booster charge for initiating the main charge, a detonator for initiating the booster charge, arming and firing means, a hand-held arm for preventing arming until the grenade is thrown, and a safety pin for locking the arm, until removed. Since the grenade is thrown, instead of being spin-launched from a rifled barrel like many explosive projectiles, one cannot utilize a safety or arming means operated by projectile spin resulting from external forces.
Brown et al, U.S. Pat. No., 2,872,866 and Kollmeyer, U.S. Pat. No. 2,991,717 each discloses a hand grenade having a fuze including a main housing containing an arming means and a torsion spring, 24 and 36, respectively, adapted, when released by the throwing of the grenade, to drive a rotary portion of the arming means to arm the grenade.
In accordance with the present invention, a hand grenade is provided with a fuze comprising a firing means, means including at least one centrifugally operated element movably carried by the grenade housing for arming the firing means, means carried by the housing for spinning the housing to operate the arming element, and manually held safety means for preventing such arming until the grenade is thrown. The means for spinning the housing comprises an inertia member, mounted on the housing for rotation relative thereto, and a torsion spring having one end attached to the inertia member and the other end detachably connected to the housing.
Two embodiments are disclosed herein having different arming and firing means but substantially the same spinning means. In one embodiment, the arming means comprises an elongated arming member mounted in a tubular support for rotation from a safe position to an intermediate position, from which it is longitudinally slidable to a final arming position. The first movement is produced by two opposed actuator plates which are operatively connected to the arming member to rotate the latter as the plates move outwardly during the spinning of the grenade, and the second movement is produced by a coil spring. In the other embodiment, an elongated arming member is longitudinally slidable in a tubular support from a safe position to an armed position. The arming member is locked in the safe position by two opposed pivoted detent arms or plates which engage locking shoulders on the arming member. As the detent arms move outwardly during the spinning of the grenade, the arming member is released and is moved by a coil spring to the armed position.